Clinical pollinosis in this country is a source of chronic discomfort for literally millions of people. One of the major offending agents associated with this condition is pollen from the short ragweed Ambrosia elatior. A number of allergens have been isolated from this pollen and two of these, Ra3 and Ra5 have been studied in some detail. The amino acid sequence and disulfide bond structure of these two relatively simple and minor allergens is nearing completion. At the same time, other investigators have utilized these allergens to determine an apparent linkage between response to Ra3 and Ra5 and possession of certain histocompatibility antigens. In addition, an attempt is being made to isolate small peptides from these allergens which retain activity for IgE. This proposal seeks to elucidate the primary and disulfide bond structure of antigen E, the major short ragweed allergen responsible for symptoms in 95% of people allergic to short ragweed. This task now appears to be feasible and timely. Besides representing the major short ragweed allergen, antigen E has been shown to possess both T cell determinants and B cell determinants, making antigen E a useful tool to study basic cell cooperation involved in immediate hypersensitivity. The long range goal is to produce haptenic determinants or immunize patients with non IgE eliciting peptides to ameliorate allergic reactions.